1. Field of the Disclosure
The present disclosure relates to barrier walls in general and in particular to a method and apparatus for monitoring the below surface connection of adjacent barrier members forming a subterranean barrier.
2. Description of Related Art
In the field of geotechnical engineering, it is frequently necessary to physically isolate one area in a soil formation from an adjacent area for a variety of purposes. These purposes may include providing either a temporary or a permanent retaining wall, or may be for the purpose of isolating contaminants in one of those areas of soil from the other. One known method of providing such isolation is to insert successive panels into the soil formation between the two areas so as to form a continuous barrier therebetween. In the case of remediation work where the purpose is to contain and remove contaminants from the soil of one of the areas, it is frequently necessary to ensure that the barrier created by such panels does not have significant gaps therebetween which may allow the contaminants to escape.
One common method of inserting such panels into the ground is to vertically orient the panel above the surface of the soil formation and apply sufficient pressure to the top of the panel so as to forcibly insert the panel into the soil formation. Successive panels may be thereafter similarly inserted into the soil formation with a slidable interconnection between the two adjacent panels to assure continuity.
A difficulty with present methods of inserting remediation panels into soil formations is their susceptibility to encountering large boulders or other subsurface objects. It is well known that encountering such subsurface objects may cause the panel to buckle or otherwise deform. Buckling of one remediation panel may cause the connector of that panel to disengage or unzipper from the corresponding connector of an adjacent panel. The resulting unzippered connection will no longer contain contaminants or other fluids thereby compromising the barrier.
Previous methods of detecting and analyzing the integrity of a connection between adjacent panels have not been satisfactory. In particular, Applicant is aware of U.S. Pat. No. 5,497,097 to Walling et al. The system of Walling et al. utilizes electrical contacts on interlocking panels to detect connection between the two panels. However, the apparatus of Walling et al. may be prone to not detecting proper connection between adjacent panels should some other material interposed between the electrical connectors. Additionally, the apparatus of Walling et al. may falsely indicate proper connection between adjacent panels in the presence of salt water or other electrolytic fluids due to the electrical fluid conducing electricity between the two electrical panels.